In production of motor vehicles, it is common practice to provide a lower portion referred to as the chassis or frame onto which are mounted many vertical structures necessary to support components, accessories and the body skin or outer shell of the vehicle. These frames require large steel stampings which are welded together into heavy structural members presenting tremendously costly transportation charges and other costs in transporting and shipping the chassis or frame for subsequent use in building the motor vehicle. Such chassis or frames can not be modified by user for the purpose of producing various vehicles. They are custom built and are used only for a special mass produced vehicle. An auto enthusiast embarking upon a project of building a custom vehicle is creatively restricted when using the frames or chassis of high production vehicles. For that reason, many enthusiasts involved in producing their own custom made cars, whether for street use, display or racing, have turned to a "space frame" for their vehicle. A space frame includes a plurality of elongated structural members cut into the desired length and welded together to produce a fabricated shell forming the total body support and lower frame of a vehicle. Since the length of the member, or struts, can be selected and the angles of the strut joints can be controlled, a space frame lends itself to extreme versatility and design creativity. The enthusiast can design a custom space frame, cut the structural pieces and weld these pieces together into any shape. Consequently, a tremendous amount of interest has been devoted to producing custom made space frames. These space frames are generally formed from structural elements, such as stainless steel pipes of various diameters, i.e. 13/4 inch diameter. Hereafter pipes will be referred to specifically, even though it is realized that these pipes may be replaced by other elongated structural members, such as bars, channels, etc.
Production of a space frame requires a substantial amount of skill together with sophisticated jigs and fixtures. Pipes cut to length are contoured at their ends to fit precisely in the desired joint location necessary to produce a total space frame. The individual pipes were located in a manner to be in either compression or tension, much like the truss of a bridge. The contouring of various ends of the pipes or struts, together with the control of the length of the various pipes used in the space frame was critical. Skilled persons with fixtures are needed to locate and support the pipes preparatory to welding. This process of building space frames for motor vehicles was normally done in a speciality shop where cutting, contouring and fitting of the various pipes comprising the total space frame were done by experienced workers.
The do it yourself home enthusiast could not make a space frame without substantial difficulty, tremendous waste material, and relatively high costs. For that reason, space frames have been limited to use by well financed enthusiasts or racing teams to the exclusion of the tremendous market made up of individuals who intend to make only one or two space frames.
In summary, there has been and is a tremendous need for a space frame which can be built by a motor vehicle enthusiast that does not require substantial skills nor high cost equipment, but which will result in a frame which is safe and functional.